Struct icu_provider::prelude::ResourceKey

pub struct ResourceKey { /* private fields */ }

Used for loading data from an ICU4X data provider.

A resource key is tightly coupled with the code that uses it to load data at runtime. Executables can be searched for ResourceKey instances to produce optimized data files. Therefore, users should not generally create ResourceKey instances; they should instead use the ones exported by a component.

ResourceKeys are created with the resource_key! macro:

const K: ResourceKey = icu_provider::resource_key!("foo/bar@1");

The human-readable path string ends with @ followed by one or more digits (the version number). Paths do not contain characters other than ASCII letters and digits, _, /, =.

Invalid paths are compile-time errors (as resource_key! uses const).

const K: ResourceKey = icu_provider::resource_key!("foo/../bar@1");

Implementations

impl ResourceKey

pub fn get_path(&self) -> &str

Gets a human-readable representation of a ResourceKey.

The human-readable path string ends with @ followed by one or more digits (the version number). Paths do not contain characters other than ASCII letters and digits, _, /, =.

Useful for reading and writing data to a file system.

pub const fn get_hash(&self) -> ResourceKeyHash

Gets a machine-readable representation of a ResourceKey.

The machine-readable hash is 4 bytes and can be used as the key in a map.

The hash is a 32-bit FxHash of the path, computed as if on a little-endian platform.

pub fn match_key(&self, key: Self) -> Result<(), DataError>

Returns Ok if this data key matches the argument, or the appropriate error.

Convenience method for data providers that support a single ResourceKey.

Examples

use icu_provider::prelude::*;

const FOO_BAR: ResourceKey = icu_provider::resource_key!("foo/bar@1");
const FOO_BAZ: ResourceKey = icu_provider::resource_key!("foo/baz@1");
const BAR_BAZ: ResourceKey = icu_provider::resource_key!("bar/baz@1");

assert!(matches!(
    FOO_BAR.match_key(FOO_BAR),
    Ok(())
));
assert!(matches!(
    FOO_BAR.match_key(FOO_BAZ),
    Err(DataError { kind: DataErrorKind::MissingResourceKey, .. })
));
assert!(matches!(
    FOO_BAR.match_key(BAR_BAZ),
    Err(DataError { kind: DataErrorKind::MissingResourceKey, .. })
));

// The error context contains the argument:
assert_eq!(
    FOO_BAR.match_key(BAR_BAZ).unwrap_err().key,
    Some(BAR_BAZ)
);

Trait Implementations

impl Clone for ResourceKey

fn clone(&self) -> ResourceKey

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ResourceKey

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for ResourceKey

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<ResourceKey> for DataRequest

Create a DataRequest to a particular ResourceKey with default options.

fn from(key: ResourceKey) -> Self

Performs the conversion.

impl PartialEq<ResourceKey> for ResourceKey

fn eq(&self, other: &ResourceKey) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &ResourceKey) -> bool

This method tests for !=.

impl Writeable for ResourceKey

fn write_to<W: Write + ?Sized>(&self, sink: &mut W) -> Result

Writes bytes to the given sink. Errors from the sink are bubbled up. The default implementation delegates to write_to_parts, and discards any Part annotations.

fn write_len(&self) -> LengthHint

Returns a hint for the number of bytes that will be written to the sink.

fn writeable_to_string(&self) -> Cow<'_, str>

Creates a new String with the data from this Writeable. Like ToString, but smaller and faster.

fn write_to_parts<S>(&self, sink: &mut S) -> Result<(), Error> where
    S: PartsWrite + ?Sized, 

Write bytes and Part annotations to the given sink. Errors from the sink are bubbled up. The default implementation delegates to write_to, and doesn’t produce any Part annotations.

impl Copy for ResourceKey

impl Eq for ResourceKey

impl StructuralEq for ResourceKey

impl StructuralPartialEq for ResourceKey